SURFACE REGOLITH AND ENVIRONMENT OF COMETS

A model for the formation of-regolith at cometary surfaces is proposed which is based on the observational fact that comet nuclei release pa rticles with sizes in the micrometre to the decimetre range. The parti cle emission mechanism is appropriated not only to accelerate particle s to escape velocity, but also to ''launch'' them into orbits above th e cometary surface and to deposite them at inactive parts of the surfa ce, forming there a regolith surface. The orbiting particles form a ne ar-surface particle-populated environment of comet nuclei.